With NUCLEO-F401RE, X-NUCLEO-CCA02M2, and STEVAL-MIC006V1, how do I set it up for 4-mic input?

[Precisely]

As per UM2631, I closed SB8 and SB10, and I opened SB9 on the CCA02M2.

In the software, I changed AUDIO_IN_CHANNELS to 4 in cca02m2_conf.h.

When AUDIO_IN_CHANNELS is 2, the two channel input works as expected (I get acoustic signals from the first 2 mics of the MIC006V1 board). With AUDIO_IN_CHANNELS set to 4, the device appears as a 4-channel input device, but all 4 channels remain 0 (there are no signals coming from the USB device).

The clock and data signals on all 4 mics look similar, regardless of the AUDIO_IN_CHANNELS value in the code.

Is there some other configuration necessary in the software? I don't see that documented anywhere. As far as I can tell, I have followed the documentation for configuration of the hardware.

Any help would be appreciated.

[Eleon BORLINI]

Hi @Precisely​ ,

Are you using the X-CUBE-MEMSMIC1 firmware function pack? In the cca02m2_conf_template.h the audio channels are already configured as 4 acquisition channels:

#define AUDIO_IN_CHANNELS 4

#define AUDIO_IN_SAMPLING_FREQUENCY 16000

-Eleon

[Precisely]

I'm building the HP_Microphones_Streaming project from STM32CubeExpansion_MEMSMIC1_v5.6.0 (your link doesn't work, but it appears to be the same version).

cca02m2_conf_template.h is just a template file. It needs to be edited for specific hardware support, renamed to cca02m2_conf.h, and copied into the project. The HP Microphone Streaming project already had a version of cca02m2_conf.h (for F401RE), with the following:

#define AUDIO_IN_CHANNELS 2

#define AUDIO_IN_SAMPLING_FREQUENCY 48000

I assumed that setting AUDIO_IN_CHANNELS to 4 would have the desired effect, but it does not (even though it looks like the code is set up to automatically configure the I2S and SPI busses to handle 2 channels, each, when AUDIO_IN_CHANNELS > 2).

I would like to know what I am missing, since I would expect that working sample code exists for this 4-mic configuration.

Ultimately, I would like to be able to stream 6-8 channels at 48 kHz, but I have not yet determined precisely which STM32 device I would need for that.

[JJérô.1]

Hello,

I have the same behavior for the AMICAM1 with 4 mems mic !

Any suggestion ??

Thanks